<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<style>style { display: none; }</style>
<style>* { display: table; }</style>
<body>Test passes if it does not crash.
<div id="log"></div>
</body>
<script>
setup({single_test: true});
document.designMode = "on";
range = document.createRange();
range.selectNodeContents(document.body);
window.getSelection().addRange(range);
document.execCommand("FormatBlock", false, "h1");
done();
</script>
